The Supreme Court has agreed to decide whether decades-old maternity leaves should count in determining pensions.

The issue has split federal appeals courts and could become increasingly important as women who took maternity leaves in the 1960's and 70's approach retirement.

Their pregnancies occurred before the federal Pregnancy Discrimination Act, enacted in 1979, barred companies from treating pregnancy leaves differently from other disability leaves. Since then, maternity leave has been credited toward retirement.

The case before the court involves four AT&T Corp. employees who each took at least one maternity leave between 1968 and 1976. They have 67-261 days of uncredited leave because their pregnancies occurred before the law changed.